Work-jogging attachments for sewing machines



April 16,1957 J. P. ENos 2,788,757

WORK-JOGGING ATTACHMENTS FOR SEWING MACHINES Filed Feb. 2, 1955 34 Fig.4

INVENTOR John F. Enos WITNESS MAM BY 4 ATTORNEY United States PatentWORK-JOGGING ATTACHL IENTS FOR SEWING MACHINES John P. Enos, Union, N.1., assignor to The Singer Manufacturmg Company, Elizabeth, N. J., acorporation of New Jersey Application February 2, 1955, Serial No.485,722

6 Claims. (Cl. 112-160) This invention relates to work-joggingattachments for sewing machines and, more particularly, to improvementsin the actuating mechanism of work-jogging attachments.

It is an object of this invention to provide means whereby attachmentparts having large manufacturing tolerances may be so positioned duringassembly that when the attachment is applied to a sewing machine, thework-jogging foot will be centered perfectly With respect to the needleaxis of the sewing machine.

With the above and additional objects and advantages in view as willhereinafter appear, this invention comprises the devices, combinationsand arrangements of parts hereinafter described and illustrated in theaccompanying drawings of a preferred embodiment in which:

Fig. 1 represents a top plan view of a work-jogging attachment in whichthe pattern cam has been removed to expose the actuating mechanism andonly a portion of the cam groove is illustrated in dot-dashed lines;

Fig. 2 represents a side elevational view of the workjogging attachmentwith the pattern cam in section and a portion of the frame and the bightcontrol slider broken away and sectioned to expose the actuatingmechanism;

Fig. 3 is an enlarged cross-sectional view taken substantially alongline 3-3 of Fig. 1; and

Fig. 4 is an enlarged cross-sectional view taken substantially alongline 4-4 of Fig. 1.

Referring to the drawings, the actuating mechanism of the presentinvention is embodied in a work-jogging attachment of the type disclosedin my copending patent application Serial No. 461,149, filed October 8,1954, to which reference may be had for a detailed description of thosefeatures of the attachment which are not directly concerned with theactuating mechanism of this invention.

The work-jogging attachment comprises a frame 11 which carries a block12 slotted to embrace a sewing machine presser bar 13 to which theattachment frame is secured by a captive thumb screw 14 in place of theusual sewing machine presser foot.

Journaled between spaced upstanding arms 1515 of the attachment frame isa stud shaft 16 to which a forked attachment actuating arm 17 issecured. As is customary in sewing machine work-jogging attachments, theforked arm is adapted to embrace a clamp 18 by which a needle 19 isremovably secured in the extremity of a sewing machine needle bar 20.Reciprocation of the sewing machine needle bar is thus harnessed tooscillate the attachment actuating arm 17.

A lug 21 struck out from the actuating arm 17 is operatively engagedbetween spaced upstandings fingers 22- 22 of a slide plate 23 which isconstrained for reciprocation on the attachment frame by a pair of slotand pin connections therewith, as indicated at 24. Pivoted at 25 to theslide plate is a pawl 26 which is biased by a spring 27 into engagementwith the teeth of a ratchet wheel 28 fast on a cam shaft 29 journaledvertically in the attachment frame. In timed relation with thereciprocation of the needle bar, step-by-step rotary motion is thusimparted ice to a pattern cam 30 which is carried by and keyed to turnwith the cam shaft 29.

The pattern cam is formed with a closed sinuous cam groove 31, it beingunderstood that the configuration of the cam groove determines thepattern of work-jogging movements effected by the attachment. The camgroove, therefore, may be of any selected configuration to produce withthe attachment any desired pattern of zigzag stitches.

This cam groove is tracked by a follower roller 32 which is journaled onfollower pin 33 fixed to one extremity of a work-jogging member 34 whichat its opposite extremity carries a work-engaging foot 35 formed with alaterally elongated needle-accommodating aperture 36. The work-joggingmember 34 is formed with an aperture 37 which is elongatedlongitudinally of the work-jogging member and is adapted to accommodatea fulcrum pin, indicated generally as 38, which is carried by a slider39 confined to move along the attachment frame. The slider may beshifted along the frame by means of a finger grip 40 to carry thefulcrum pin to any selected position along the aperture 37. A thumbscrew 41 which passes through a slot 42 in the slider and is threadedinto the frame provides a means by which the slider may be clamped inany selected position of adjustment. Thus, by changing the ratio of thelever arms presented by the shank member, the extent of work-joggingmovement or bight which the work-jogging foot partakes may be adjusted.The slider 39, however, when clamped in any selected position ofadjustment becomes, for all intents and purposes, a part of theattachment frame, and the fulcrum pin 38, therefore, may be consideredas being secured to the attachment frame.

Pivoted on the cam follower pin 33 is one extremity of an anchor link 43of which the opposite extremity is pivoted to the attachment frame bymeans of a pivot pin,

, indicated generally as 44.

The quality of the pattern of stitches which will be formed with the useof the above described attachment depends primarily upon the degree ofcontrol which the work-engaging foot 35 can maintain over the workfabric at the stitching point. Any puckering or shifting of the workfabric with respect to the foot during the workjogging motion willdetract from the quality of the stitching and from this standpoint it isadvantageous to form the needle-accommodating aperture 36 no bigger thanis absolutely necessary to accommodate the widest bight of which theattachment is capable. To make the aperture 36 any larger would undulyincrease the area of unsupported fabric adjacent to the needle and wouldthus diminish the control by the work-engaging foot over the workfabrics.

It will be apparent that to tolerate a needle-accommodating aperture 36of minimum dimensions, the workengaging foot must be positioned when theattachment is applied to a sewing machine such that the path ofreciprocation of the sewing machine needle will be centered in theaperture 36, that is, centered not only between the front and rearsidewalls of the laterally elongated aperture 36 but centered so that atthe widest bight the needle does not strike the work-engaging foot ateither end of the elongated aperture 36.

To manufacture each of the attachment parts to sufliciently closetolerances that upon assembly centering of the needle-accommodatingaperture could be assured would be prohibitively expensive. It should beborne in mind that the dimensions of many of the parts contribute todictate the needle-accommodating aperture position and that thetolerances may be cumulative.

In the past, it has been the practice physically to distort theassembled attachment until the requisite alignment is attained. Thisprocedure has several disadvantages in 7 portion 56 upset.

that it is not always possible to control the distortion so thatitsometimes adversely affects attachment operation. Furthermore, asurprising high degree of skill is necessary for such adjustment bydistortion so that it not only results iii inetficie'nt' utilization ofmanpower but. sharply increases labor costs in production. A i

The present invention provides a means whereby the work-engaging-footmay be aligned as a simple adjunct to the assembly of the parts withoutdistortion of the parts and in. a'manner which does not require specialcapabilitieson the part of an assembly worker.

In the present invent'ion both the f ul crum pin 38 and the anchorlinkpivot; pin 44 are provided in a novel,

'rnannerwith eccentric-portions which when; positioned during assemblyprovide for a'perfe'ct alignment of the work-engaging foot with respectto the path of reciprocation of the sewing machine needle.

Referring more particularly to Fig. 4, the fulcrum pin 38 is providedwith a shankportion 45 which is eccentrically. disposed with respect tothe axis of the remainder of the parts-of the fulcrum pin. The eccentricportion 45 isdisposed inengagement with the slot 37 formedlongitudinally in the work-jogging member 34. In the preferredembodimentof the drawings, the fulcrum pin 38 takes the form of a rivetand is formed with a shank portion 47 adapted to enter an aperture 48formed in the slider 39 and 'to be secured thereto by having the shankportion47 upset in the usual fashion of'a rivet. The fulcrum pin 38isformed with an enlarged head 49' formed with a screw driver slot 50 sothat the pin may be turned in assembly to center the aperture 36 in alateral direction with respect to the path of needle reciprocation. Theslider aperture 48 is formed with a plurality of radially extendingnotches 51 -5l, Fig. 4, so that upon being upset the shankportion 47 ofthe fulcrum pin will be locked in the particular selectedangularpositionwith respect to the slider; and hence with respect to the attachmentframe. As to this form of rotational interlock between the fulcrum pinand the attachment frame, I donot desire to be limited to the notchedconstruction which is illustrated and it will be understood that anyform of aperture 48 which -is noncircular will serve this purpose.

Since the fulcrum pin 38 servesto dictate the bight or the extentoflateral movement of the stitch pattern, there will be a differencenoticeable at the smallest and largest bight settings from oneattachment to the next unless the eccentricity of the shank portion 45of the fulcrum pin is consistently made to occur' on the same side ofthe axis of the fulcrum pin. For this purpose, a curved notch 52 isformed'in the fulcrum pin head 49, the notch being located at a pointopposite the point of maximum eccentricity of the eccentric portion 45.positioning the indicia 52 consistently either to the front of theattachment, as illustrated in the drawings, or consistently to the rear,then all of the attachments so made will have consistene bight settingsand bight ranges.

In Fig, 3 is illustrated theconstruction of the anchor link pivot pin44. The pin 44 is formed with a head portion 53 having a screw driverslot 54 and a shank portion 55 which together with the head 53 isdisposed eccentrically with respect to a shank portion 56 which isadapted to enter an aperture 57 in the attachment frame'and to besecured thereto by having the shank A washer 58 and the anchor link 43aredisposed inengagement with the eccentric shank portionS S of thepivot pin 44 and the aperture 57 of the attachment frame is formed withradial notches 59 or amy be otherwise made noncireular so that the pivotpin will belocked with respect to the framein the particular selectedangular position when the shank portion 56 is upset. The eccentric pivotpin 44 thereby provides ameans for centering the sides of theneedle-accommodating slot with respect to the path of needlereciprocatron.

By arbitrarilythe form of a lever, a rivet secured with respect to saidattachmentframe and associated with said workejogging member to providea fulcrum for movement thereof,

mechanism carried by said attachment frameformoving said work-ioggingmember about said fulcrum, a-workengaging foot carried by saidwork-jogging member; and having 'a needle-accommodating aperture formedtherein,

. and means for'center-ing saidaperture'with respect to' the path ofreciprocationofsaid sewingmachine needle,.comprising an eccentricportion formed on said fulcrum rivet, said eccentric portion beingdisposed in operative engagement withsaid work-jogging. member, a shankportion formed on said rivet adapted to be upset to secure said. rivetwith respect to said attachment frame, said. attachment. frame beingformed with anoncircular rivet accommodating aperture whereby upsetting;of said rivet shank will secure said. fulcrum pin permanently in anyselected,

angular position with respectqto. said attachment frame. 2. Awork-joggingjattachment. for a sewing machine.

as set forth in claim 1 in whichthe fulcrum. pin is-provided withindicia marking thefpoint of maximum eccentricity of said eccentricportion- 3. A work-jogging attachment for a sewing machine having anendwise reciprocatory needle, said attachment having an attachment frameadapted to be secured to. said sewing machine, a. work-jogging member, awork engaging foot. carried. by said member, said work-en gaging footbeing formed with a needle-accommodating,

aperture, a fulcrum pin. secured, to said frame, said worlo.

jogging member being formed with a fulcrum pin-accommodating aperturewhich is elongated. longitudinally.-

of said member, mechanism. carried by said attachment.

frame for vibrating said work-jogging member laterally, v an anchorlink; pivotally connected at one extremity to said'work-jogging member,a pin secured to .said attach-. ment frame and pivotally connected withthe other extremity of said anchor link to constrain said work-joggingmember longitudinally, and means forcentering said needle-accommodatingaperture with respectto the path of reciprocation of said needlecomprising an eccentric portion formed on said'pivot pin, said eccentricportion being disposed inpivotal engagement with said." anchor link, andmeans for securing said pivot pin in any selected angular position withrespect to said attachement frame.

4. A work-jogging attachment for a sewing machine as set forth in claim3 in which said pivot .pin takes the form of a rivet, a shank portionformed on. said rivet adapted to be upset to securesaid rivet withrespect'to said attachment frame, said attachment frame being formedwith a noncircular rivet accommodating aperture whereby. upsetting ofsaid rivet shank will secure said pivot 'pin permanently. in anyselected angular position with respect tosaid attachment frame. 7

5; A work-jogging attachment as set forth in claim 3 in which both said.pivot pin and said fulcrum pin are" provided with: eccentric portions,the eccentric portion of said fulcrum pin being disposed in operativeengagement with saidwork-jogging member, the eccentric portion of saidpivot-pinbeing disposed in pivotal engagement with said anchor link, andmeans for securing each of said pins; in any selected angular positionwith respect to saidfat tach'ment frame.

6. A work-jogging attachment for a sewingmachinehavingan endwisereciprocatory needle, said attachment having an attachment frame adaptedto be secured to said" sewing machine, a work-jogging member, aworkengag ing footcarriedby said member, said work-engaging; foot beingformed with a needle accommodating aperture, a fulcrum member carried bysaid frame, said work:

jogging member being formed with a fulcrum member accommodating aperturewhich is elongated longitudinally of said Work-jogging member, mechanismcarried by said attachment frame for moving said Work-jogging memberabout said fulcrum member, an anchor link pivotally connected at oneextremity to said work-jogging member, an anchor link securing membercarried by said frame and connected with the other extremity of saidanchor link, and a first and second centering means, said first meansbeing interposed between said fulcrum member and said frame, said secondmeans being interposed between said anchor link securing member and saidframe,

References Cited in the file of this patent UNITED STATES PATENTS678,908 Rose et al. July 23, 1901 740,298 Moore Sept. 29, 1903 2,660,138Russell Nov. 24, 1953

